Sergio Aguero has stepped up his training regime in a bid to recover from his thigh injury and help Argentina's World Cup bid - before it is too late.

The 26-year-old has been seen working on a treadmill at Argentina's training base, raising hope that he will be available for the later stages of the tournament should Alejandro Sabella's side get there.

Aguero limped off towards the end of the first half during Argentina's win against Nigeria in their final Group F match and had to be replaced by Ezequiel Lavezzi.

Treatment: Aguero went down injured seven minutes before the break against Nigeria on Wednesday

Replacement: Lavezzi came on for the Manchester City striker, but his injury may not be as bad as first feared

Reports in Argentina and Italy suggested the Manchester City attacker might miss the rest of the tournament with a muscle tear, but Argentina's team doctor Daniel Martinez moved to quell those fears in a press conference on Thursday.

'It's a first-degree muscle strain in his femoral biceps,' Martinez. 'It's a degree lower within the muscular injuries.

'He will try to recover as soon as possible. We have all the available resources in order to get Sergio fit as soon as possible. The recovery already started on Wednesday.

'From Switzerland onwards, it will depend on whether Argentina remains in the competition and on his day-to-day recovery in order to see him back on the pitch.'

Argentina face Switzerland in the last 16 on Tuesday.

Fitness bid: Aguero is working on a treadmill to lift his fitness and try to play again at this World Cup